Production of cyclic trimers of 1,3-dienes

ABSTRACT

A 1,3-DIENE IS CAUSED TO CONTACT A CATALYST SYSTEM COMPRISING, IN COMBINATION: A TITANIUM COMPOUND   TI(O-R-CL)NCL4-N   (WHERE R IS AN ALKYLENE, CYCLOALKYLENE, CHLOROALKYLENE OR CHLOROCYLOALKYLENE GROUP OF C2 TO C15, AND N IS 1 OR 2); AN ORGANOALUMINUM COMPOUND AIR&#39;&#39;MCL3-M (WHERE R&#39;&#39; IS AN ALKYL GROUP OF C1 TO C10, AND M IS 2 OR 1.5); AND AN ADDITIVE WHICH IS A SULFOXIDE SOR&#34;2 (WHERE R&#34; IS AN ALKYL OR ARALKYL GROUP OF C1 TO C10) OR A MIXTURE THEREOF AND A PHOSPHINE OXIDE POR&#39;&#39;&#34;3 (WHERE R&#34; IS AN ALKYL, ARALKYL, OR ALKOXY GROUP OF C1 TO C10), THE 1,3-DIENE THERBY UNDERGOING CYCLIC TRIMERIZAYION WHEREBY A CYCLIC TRIMER OF LOW CONTENT OF HIGH POLYMERS IS PRODUCED AT HGIH REACTION VELOCITY AND WITH HIGH SELECTIVITY.

United States Patent 3,823,196 PRODUCTION OF CYCLIC TRIMERS OF 1,3-DEENES Hiroyuki Morikawa and Takao Saito, Ami, Japan, as-

signors to Mitsubishi Petrochemical Company Limited, Tokyo-to, Japan No Drawing. Filed June 7, 1971, Ser. No. 150,802 Claims priority, application Japan, June 18, 1970, 45/52,395 Int. Cl. C07c 3/00 US. Cl. 260--666 B 9 Claims ABSTRACT OF THE DISCLOSURE A 1,3-diene is caused to contact a catalyst system comprising, in combination: a titanium compound (where R is an alkylene, cycloalkylene, chloroalkylene or chlorocycloalkylene group of C to C and n is 1 or 2); an organoaluminum compound AlR',,,Cl;., (where R is an alkyl group of C to C and m is 2 or 1.5); and an additive which is a sulfoxide SOR' (where R" is an alkyl or aralkyl group of C to C or a mixture thereof and a phosphine oxide POR (where R" is an alkyl, aralkyl, or alkoxy group of C to C10), the 1,3-diene thereby undergoing cyclic trimerization whereby a cyclic trimer of low content of high polymers is produced at high reaction velocity and with high selectivity.

BACKGROUND OF THE INVENTION This invention relates generally to the production of oligomers of 1,3-dienes and more particularly to a new and advanced process for producing cyclic trimers of 1,3-dienes while suppressing the formation of high polymers.

The terms oligomers and trimers as used throughout this disclosure are intended to include, respectively, homooligomers and cooligomers and homotrimers and cotrimers.

It is known to synthesize cyclic trimers of 1,3-dienes by using Ziegler-type catalysts comprising combinations of titanium compounds and organoaluminum compounds. More specifically, examples of use of titanium halides and alkoxides are disclosed in Japanese Pat. Publication No. 2372/1960 TiCl AlEt Cl), Japanese Pat. Publication No. 7765/1964 (Ti(OC ,H AlEt Cl), Japanese Pat. Publication No. 19331/ 1965 (Ti(C I-I O Cl AlEt Cl), and other publications.

These Ziegler-type catalyst comprising titanium compounds and organoaluminum compounds have extremely high activity in comparison with nickel catalysts and are therefore advantageous.

However, these Ziegler-type catalysts simultaneously have high activity also for the formation of high polymers and thereby have the disadvantage of readily causing the formation of by-products other than the objective oligomers.

Accordingly, with the object of overcoming this drawback, a method of adding compounds having semipolar double bonds to catalyst systems of titanium halides and alkylaluminum halides (as disclosed in the Japanese Patent Publication No. 17974/ 1962) and a method of adding Lewis bases (as disclosed in the Japanese Pat. Publication No. 22656/ 1965 have been proposed. The modification effect due to these additives is indicated as respectively differing depending on the type of the titanium compound.

Among catalyst systems in which additives are used, there has been a tendency for those of good selectivity of cyclic trimers to produce a low reaction velocity and those of high reaction velocity to have poor selectivity.

3,823,196 Patented July 9, 1974 SUMMARY OF THE INVENTION It is an object of this invention to overcome the above described difficulties encountered in the prior art in providing a new and advanced process for producing cyclic trimers of 1,3-dienes with low content of high polymers. This object and other objects of this invention have been achieved through the use of catalysts comprising combinations of specific titanium compounds, specific organic aluminum compounds, and specific additives.

According to this invention, briefly summarized, there is provided a process for producing cyclic trimers of 1,3-dienes wherein a 1,3-diene is caused to undergo cyclic trimerization by contacting a catalyst system comprising, in combination: a titanium compound (I) representable by the general formula where R is an alkylene group, a cycloalkylene group, a chloroalkylene group or a chlorocyclo alkylene group of from C to C and n is 1 or 2; an organoaluminum compound (II) representable by the general formula AlR' Cl where R is an alkyl group of from C to C1 and m is 2 or 1.5; and an additive (III) which is a sulfoxide (III-1) representable by the general formula SOR where R" is an alkyl group or an aralkyl group of from C to C or a mixture of a sulfoxide (III-l) and a phosphine oxide (III-2) representable by the general formula POR" where R'" is an alkyl group, an aralkyl group, or an alkoxy group of from C1 to C10.

The nature, principle, and utility of this invention will become more clearly apparent from the following detailed description beginning with a consideration of general aspects and features of the invention and concluding with specific examples of practice illustrating preferred embodiments thereof.

DETAILED DESCRIPTION As summarized briefly hereinabove, the catalyst system according to this invention comprises a combination of specific constituents or components. Heretofore, nothing has been known with respect to the catalytic effect of titanium compounds having chloroalkoxy ligands of this type. Furthermore, the efi'ectiveness of adding a specific sulfur compound or a mixture thereof with a specific phosphorus compound to this catalyst system has heretofore been totally unknown.

We have found that through the use of a catalyst system of the composition according this invention, cyclic trimers of 1,3-dienes can be produced at a high reaction velocity, with high selectivity, and with only a small quantity of lay-product high polymers.

CATALYST Component I One (component I) of the components of the catalyst system used in this invention to produce high desirable effects is a titanium compound representable by the gen eral formula Ti(ORCl) Cl where R is an alkylene group, a cycloalkylene group, chloroalkylene group or chlorocycloalkyelne group of a number of carbon atoms from 2 to 15, and n is l or 2. A chloroalkoxytitanium chloride representable by this general formula, in general, has the characteristics of solubility, high catalytic stability, and, at the same time, high activity for formation of oligomers.

A titanium compound of this character is prepared by reaction of TiCl, and a corresponding alkylene oxide by utilizing the process set forth in the UnitedStates Pat. No. 2,709,174. More specifically, such a titanium compound can be readily produced by any one of the reactions as indicated below, for example,

T1014 om-on-omcr Ti(OCH(CHzC1)CHzCI)Cla The number of chloroalkoxy ligands for producing the optimum catalytic effect in terms of n is l or 2, while a value of n of 3 or 4 lowers the activity of the catalyst for oligomer production. Substitution of ethylene oxide by a cycloal kylene oxide preferably of C to C from the view point of cyclododecatriene yield, such as cyclohexene oxide, produces a corresponding chlorocycloalkylenoxytitanium chloride.

Examples of such compounds are:

chloroethoxytrichlorotitanium [Ti(OC H Cl)Cl synthesized from ethylene oxide and titanium tetrachloride;

di(chloroethoxy) dichlorotitanium [Ti (OC H CI) Cl synthesized from chloroethoxytrichlorotitanium and ethylene oxide;

chloropropoxytrichlorotitanium [Ti OC3H7CI) Cl synthesized from propylene oxide and titanium tetrachloride;

di- (chloropropoxy) dichlorotitanium [Ti (OC H Cl Cl synthesized from chloropropoxytrichlorotitanium and propylene oxide;

chlorobutoxytrichlorotitanium [Ti( OC H Cl) C1 synthesized from butylene OXide and titanium tetrachloride;

dichloropropoxytrichlorotitanium [Ti(OC H Cl )Cl synthesized from epichlorohydrin and titanium tetrachloride; and

chlorododecenyltrichlorotitanium [Ti (OC H Cl) C1 synthesized from dodecene oxide and titanium tetrachloride.

chlorocyclobutenoxytitanium trichloride chlorocyclopentenoxytitanium trichloride chlorocyclohexenoxytitanium trichloride chlorocyclooctenoxytitanium trichloride di-(chlorocyclobutenoxy) titanium dichloride di-(chlorocyclopentenoxy) titanium dichloride di-(chlorocyclohexenoxy) titanium dichloride di-(chlorocyclooctenoxy) titanium dichloride These compounds can be used singly or as mixtures of two or more thereof.

Component II dimethylaluminum chloride; methylaluminum sesquichloride; diethylaluminum chloride; ethylaluminum sesquichloride; diisobutylaluminum chloride; butylaluminum sesquichloride; and dioctylalumminum chloride.

These compounds can be used singly or as mixtures of two or more thereof.

Component III The third component (component III) of the instant catalyst is a sulfoxide used singly or is a combination of a sulfoxide and a phosphine oxide type compound. It is our conclusion that the use of this component III produces the effect of suppressing the by-produetion of high polymers and increasing the reaction velocity.

dimethyl sulfoxide; dipropyl sulfoxide;

These compounds can be used singly or as mixtures of two or more thereof.

(2) Phosphine oxides A phosphine oxide type compound to be used together with the sulfoxide is a compound representable by the general formula POR"' where R' is an alkyl group,

an aralkyl group, or an alkoxy group. Examples of such compounds are:

trimethylphosphine oxide triethylphosphine oxide tripropylphosphine oxide tributylphosphine oxide triphenylphosphine oxide tricresylphosphine oxide trimethyl phosphate triethyl phosphate tributyl phosphate triphenyl phosphate tricresyl phosphate These compounds can be used singly or as mixtures of two or more thereof.

Ratio of the components The ratio of the quantities of the titanium compound (I) and the aluminum compound (II) used in the catalyst system of this invention can be varied over a wide range. For example, the range in terms of mole ratio of Al compound/Ti compound=l to 100, preferably 3 to 10.

The quantity of the additive (III) in terms of mole ratio is as follows. In the case of a sulfoxide or a mixture of sulfoxides, by itself, S compound/Ti compound=0.01 to 4, preferably 0.1 to 1. In the case where one or more sulfoxides and one or more phosphine oxides are used together, (P compound, S compound) Ti compound=0.01 to 4, preferably 0.1 to 1.

The composition of the additive mixture, in terms of mole ratio, is in the range of P compound/S compound=0.1 to 10, preferably 0.3 to 3.

Preparation In the preparation of the catalyst, the additive (III) may be added to each of the other components of the catalyst, or it may be added before or after admixing of the titanium compound and the aluminum compound. Ordinarily, the preferable procedure is to add the aluminum compound to a mixed solution of the titanium compound and the additive.

TRIMERIZATION While a cyclic trimerization reaction due to the catalyst system can be carried out irrespective of the presence or absence of a solvent medium, it is ordinarily suitable to carry out the reaction in the presence of a solvent. Examples of preferable solvents for this purpose are aromatic hydrocarbons such as benzene, toluene, and xylene and aliphatic hydrocarbons such as hexane and heptane.

While the temperature of the cyclic trimerization reaction can be varied within a range of from 0 to C., a preferable range is from 20 to 70 C. The reaction can be carried out under atmospheric pressure or higher pressure.

Examples of 1,3-dienes which are monomers to undergo cyclic trimerization are butadiene-(1,3), isoprene, pentadiene-(1,3), and mixtures thereof. Furthermore, the term 1,3-dienes is herein interpreted to include lowgrade or impure butadiene-(1,3) mixtures (e.g., plant BB fraction) containing olefins, such as butene-l and butene-Z, up to 25 to 90% by mole of butadiene-1,3. We have found that when the process according to this invention is carried out with the use of these 1,3-diene mixtures and low-grade or impure dienes as starting materials, cyclic homotrimers and cyclic cotrimers can be produced in a particularly satisfactory manner, while the formation of by-product reaction products is suppressed.

EXAMPLES .In order to indicate more fully the nature and utility of this invention, the following comparative example based on experiments and specific examples of practice constituting preferred embodiments of the invention are set forth, it being understood that these examples are presented as illustratively only and that the details set forth Percent Methylcyclododecatriene 52 Dimethylcyclododecatriene 2 Cyclododecatriene 46 Example 3 The process set forth in Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of di-(chloroethoxy)dichlorotitanium, 0.15 millimole of triphenylphosphine oxide, 0.15 millimole of dimethyl sulfoxide, 5 millimole of diethylaluminum chloride, and 12 g. of butadiene.

As a result, 10.8 g. of cyclododecatriene-(1,5,9) is obtained, yield being 90%.

Example 4 therein are not intended to limit the scope of the invention. 15 The process according to Example 3 except f the use of a mixture of 14 g. of butadiene and 9 g. of isoprene as Comparatwe Examp Ie the monomer is carried out.

Reaction conditions1 millimole of the titanium com- As a result, 17.2 g. of a cyclic trimer fraction is obpound, 5 millimoles of diethylaluminum chloride, 50 cc. tained, yield being 75%. The composition of this trimer of benzene, reaction temperature of 40 C., and reaction fraction is as follows. time of 3 hours. Percent Under the above reaction conditions, reactions were Methylcyclododecatriene 41 carried out with the following starting materials. Dimethylcyclododecatriene 1 Experiment No. Starting material Cyclododecatnene 58 Exp. 1 1,3-butadiene (12 g.) Exam 1e 5 Exp. 2 butadiene (14 g.)+pentadiene (9 g.) p Exp 3 BB f ti A process similar to that of Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of chloroof the BB fractmni 30 propoxytrichlorotitanium, 0.1 millimole of triphenylphos- Percent phine oxide, 0.2 millimole of diphenyl sulfoxide, 10 milli- Propylene 0.9 moles of diethylaluminum chloride, and 12 g. of butadiene Methylacetylene 0.4 at a reaction temperature of 50 C. Butane 8 As a result, 10.9 g. of cyclododecatriene-(1,5,9) is ob- Isobutane 2 tained, yield being 91% Butene-l 17 E 1 6 Isobutylene 28 Xamp e Butene-2 6 Under the same conditions as those set forth in Example Butadiene 37 5, reaction is carried out through the use of 30 g. of a BB Others Remainder 40 fraction which is a mixture of 0.9% propylene, 0.4%

Tetra- Tetra- Chloroethoxytrichloroethoxychloro- Titanium compound titanium (this invention) titanium titanium Additive quantity (millimole):

Dimethyl sulfoxide 0. 2 0. 2 0. 2 0. 2

Triphenylphosphine oxide 0. 2 0. 2 0. 2 0. 2 Cyclic trimer m'eld (weight percent):

Example:

............ 73 58 as 36 4s Example 1 methylacetylene, 8% butane, 2% isobutane, 17% butene- A pressure-resistant bottle of 150-cc. capacity is purged 2 lsobutykne 6% butene2 and 37% of butadiene with nitrogen and charged with cc. of benzene, 1 milli e i 5 1 dod t 1 5 9 b mole of chloroethoxytrichlorotitanium, 0.2 millimole of t ig i 3 q eca 1S 0 triphenylphosphine oxide, 0.2 millimole of dimethyl sul- 1 g yle emg W1 respect to utadlene foxide, 5 millimoles of diethylaluminum chloride, and 12 P g. of butadiene. The resulting mixture is then agitated for Example 7 3 3 9; 2 9 n01 olution is added to the recess The process of Example 1 is carried with the use of 50 t i z catal St and after congentra cc. of benzene, 1 millimole of chloropropoxytrichloro- 0 p titanium, 0.07 millimole of tributylphosphine oxide, 0.1 tion of the solvent, fractlonal d1st1llat1on of the resulting millimole of diphenyl sulfoxide, 5 milhmoles of diethylprocess materials 1s carried out under reduced pressure.

. aluminum chloride, and 50 g. of a BB fraction of the same As a result, 11 g. of a cyclododecatr1ene-( 1,5,9) fraccomposition as that in Example 6. tron having a boilingpoint offrom to C. (at mm. 65 As a result 9 4 g of cycle do decatriene (1 5 9) is Hg) is obtained. ThlS quantity corresponds to a yield of tamed ield 92 percent with respect to the monomer charged. y g

Example 2 Example 8 The procedure according to Example 1 is followed ex- The process of Example 1 is carried out with the use cept for the use of a mixture of 14 g. of butadiene and 70 of 50 cc. of benzene, 1 millimole of chloropropoxytri- 9 g. of pentadiene for the monomer. chlorotitanium, 0.1 millimole of triethylphosphine oxide,

As a result, 16.8 g. of a cyclic trimer fraction of a boil- 0.3 millimole of diethylsulfoxide, 10 millimoles of ethyling point of from 50 to C. at 2 mm. Hg, is obtained, aluminum sesquichloride, and 30 g. of a BB fraction of the yield being 73 percent. The composition of this cyclic same composition as that in Example 6 and with a reactrimer fraction is as follows. 75 tion temperature of 60 C.

7 As a result, 9.65 g. of cyclododecatriene-(1,5,9) is obtained, yield being 87% Example 9 The process of Example 1 is carried out with the use of 50 cc. of toluene, 1 millimole of di-(chloropropoxy)dichlorotitanium, 0.1 millimole of tricresylphosphine oxide, 0.3 millimole of diethyl sulfoxide, millimoles of ethylaluminum sesquichloride, and 12 g. of butadiene and with a reaction temperature of 70 C.

As a result, 10.8 g. of cyclododecatriene-( 1,5,9) is obtained, yield being 90% Example 10 The process of Example 1 is carried with the use of 50 cc. of toluene, 1 millimole of dichloropropoxytrichlorotitanium, 0.3 millimole of triphenylphosphine oxide, 0.6 millimole of dimethyl sulfoxide, 5 millimoles of diethylaluminum chloride, and 12 g. of butadiene with a reaction temperature of 50 C.

As a result, 10.6 g. of cyclododecatriene-(1,5,9) is obtained, yield being 88% In an instance of practice wherein the above process was carried out without the triphenylphosphine oxide, 9.1 g. of cyclododecatriene-(1,5,9) was obtained, yield being 76%.

Example 11 The process of Example 1 is carried out with the use of 50 cc. of toluene, 1 millimole of di-(chlorobutoxy)di chlorotitanium, 0.1 millimole of triphenylphosphine oxide, 0.2 millimole of dimethyl sulfoxide, 8 millimoles of diisobutylaluminum chloride, and 12 g. of butadiene and with a reaction temperature of 70 C.

As a result, 10.4 g. of cyclododecatriene-(1,5,9) is obtained, yield being 87 Example 12 The process of Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of chlorododecenyltrichlorotitanium, 0.2 millimole of triphenylphosphine oxide, 0.4 millimole of dimethyl sulfoxide, 10 millimoles of ethylaluminum sesquichloride, and 12 g. of butadiene.

As a result, 10.3 g. of cyclododecatriene-(1,5,9) is obtained, yield being 86% Example 13 The process of Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of chlorobutoxytrichlorotitanium, 0.2 millimole of tricresylphosphine oxide, 0.2 millimole of dimethyl sulfoxide, 5 millimoles of diethylaluminum chloride, and g. of isoprene.

As a result, 10 g. of trimethylcyclododecatriene of a fraction of a boiling point from 80 to 100 C. at 2.5 mm. Hg is obtained, yield being 67% Example 14 The process of Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of di-(chloropropoxy) dichlorotitanium, 0.2 millimole of tributylphosphine oxide, 0.2 millimole of dimethyl sulfoxide, 5 millimoles of diethylaluminum chloride, and 15 g. of pentadiene.

As a result, 8.6 g. of trimethylcyclododecatriene is obtained, yield being 57% Example 15 The process of Example 1 is carried out with the use of 50 cc. of benzene, 1 millimole of chlorobutoxytrichlorotitanium, 0.1 millimole of tricresyl phosphate, 0.3 milli' mole of dimethyl sulfoxide, 5 millimoles of diethyla1uminum chloride, and 12 g. of butadiene.

As a result, 10.4 g. of cyclododecatriene-(1,5,9) is obtained, yield being 87%.

Example 16 The process of Example 1 is carried out with the use of 50 cc. of toluene, 1 millimole of chloroethoxytrichlorotitanium, 0.1 millimole of tributyl phosphate, 0.3 millimole of dimethyl sulfoxide, 10 millimoles of diethylaluminum chloride, and a mixture of 14 g. of butadiene and 7 g. of pentadiene.

As a result, 15.5 g. of a cyclic trimer fraction of a boiling point of from 50 to C. at 2 mm. Hg is obtained, yield being 74%. The composition of this trimer fraction is as follows. I

Percent Methylcyclododecatriene 56 Dimethylcyclododecatriene 1 Cyclododecatriene 43 Example 17 In an instance of practice, the process of Example 10 was carried out without the use of the triphenylphosphine oxide, whereupon 9.1 g. of cyclododecatriene-(1,5,9) was obtained, yield being 76%.

Example 18 An autoclave of 500 cc. capacity is purged with nitrogen, and charged with 100 cc. of benzene, 0.288 g. of chlorocyclohexenoxytitanium trichloride, 0.606 g. of diethylaluminum chloride, 0.026 g. of triphenyl phosphate, and 0.064 g. of dimethylsulfoxide. The resulting mixture is then agitated.

To the thus prepared mixture, 60 g. of BB fraction is then introduced and agitated for 2 hours at 75 C. The composition of the BB fraction is: 1,3-butadiene 37%, butane-l-butene 62.1%, allen 0.2%, methylacetylene 0.1%, ethylacetylene 0.1%, and vinyl acetylene 0.4%.

Thereafter, methanol is added to the process material to decompose the catalyst.

14.9 g. of a cyclododecatriene-(1,5,9) fraction having a boiling point of 235 to 250 C. and having a purity of 99.6% is obtained out of the process material by distillation. Yield of the pure CDT produced is 67.1 percent with respect to the butadiene charged.

Example 19 The procedure according to that of Example 18 is followed except for the use of 0.314 g. of chlorocyclooctenoxytitanium trichloride for the titanium compound.

As a result, 15.4 g. of a CDT fraction of 99.1% purity is obtained. Yield is 73%.

Example 20 The process set forth in Example 18 is carried out with the use of 0.274 g. of chlorocyclopentenoxytitanium trichloride for the titanium compound.

As a result, 15.0 g. of a CDT fraction of 99.4% purity is obtained. Yield is 67.2%.

Example 21 The process set forth in Example 18 is carried out with the use of 100 cc. of toluene, 0.288 g. of chlorocyclohexenoxytitanium trichloride, 0.606 g. of diethylaluminum chloride, 0.02 g. of tributylphosphine oxide, 007 g. of diphenyl sulfoxide, and the same BB fraction as that used in Example 18.

As a result, 14.1 g. of a CDT fraction of 99.1% purity is obtained. Yield is 63 Example 22 Example 23 The process of Example 18 is carried with the use of 100 cc. of toluene, 0.314 g. of chlorocyclooctenoxytitanium trichloride, 0.035 g. of tricresylphosphate, 0.06 g. of dimethyl sulfoxide, 1.12 g. of ethylaluminum sesquichloride, and 60 g. of a BB fraction of the same composition as that in Example 18.

As a result, 13.6 g. of a CDT fraction of 98.7% purity is obtained. Yield is 60.5%.

What is claimed is:

1. A process for producing cyclic trimers of 1,3-dienes which comprises carrying out cyclic trimerization of a 1,3-diene by causing the same to contact a catalyst system comprising, in combination:

a titanium compound (I) representable by the general formula Ti(O-R-Cl) Cl where R is a member selected from the group consisting of alkylene, cycloalkylene, chloroalkylene, and chlorocycloalkylene groups of from C to C wherein the oxygen and chlorine (Cl) atoms are separated by a carbon bridge containing two carbon atoms, and n is an integer less than 3;

an organoaluminum compound (II) representable by the general formula AlR' C1 where R is an alkyl group of from C to C and m is a number selected from the group consisting of 3 and 1.5; and

an additive (III) which is a member selected from the group consisting of sulfoxides (III-1) each representable by the general formula S0R where R is a member selected from the group consisting of alkyl and aralkyl groups of from C to C10 and mixtures of a sulfoxide (HI-1) and a phosphine oxide (HI-2) representable by the general formula PO where R' is a member selected from the group consisting of alkyl, aralkyl, and alkoxy groups of from C to C 2. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which said titanium compound (I) is representable by the general formula where R is a member selected from the group consisting of alkylene and chloroalkylene groups of from C, to C wherein the oxygen (0) and chlorine (Cl) atoms are separated by a carbon bridge containing two carbon atoms, and n is an integer less than 3.

3. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which said titanium compound (I) is representable by the general formula where R is a member selected from the group consisting of cycloalkylene and chlorocycloalkylene groups of from 10 C to C wherein the oxygen (0) and chlorine (Cl) atoms are separated by a carbon bridge containing two carbon atoms, and n is an integer less than 3.

4. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which the mole ratio aluminum compound (ID/titanium compound (I) is from 1 to 100, and the mole ratio sulfoxide (III-1)/titanium compound (I) is from 0.01 to 4.

5. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which the mole ratio aluminum compound (ID/titanium compound (I) is from 1 to 100, the mole ratio phosphine oxide (III-2)/sulfoxide (Ill-1) is from 0.1 to 10, and the mole ratio (phosphine oxide (III-2)+sulfoxide (III-1))l titanium compound (I) is from 0.01 to 4.

6. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which the 1,3-diene is butadiene, and the cyclic trimer of 1,3-dienes is cyclododecatriene- 1,5,9.

7. A process for producing cyclic trimers of 1,3-dienes according to Claim 6 in which the butadiene is in the form of a mixture thereof with butenes.

8. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which the 1,3-diene is a methylsubstituted butadiene, and the cyclic trimer of 1,3-dienes is a methyl-substituted cyclododecatriene-1,5,9.

9. A process for producing cyclic trimers of 1,3-dienes according to Claim 1 in which the 1,3-diene is a mixture of butadiene and a methyl-substituted butadiene, and the cyclic trimer of 1,3-dienes is a mixture of cyclododecatrims-1,5,9 and a methyl-substituted cyclododecatriene- 1,5,9.

References Cited UNITED STATES PATENTS 3,644,548 2/ 1972 Takanasi et a1. 260-666 B 3,641,187 2/1972 -Furukawa et a1. 260-666 B 3,642,924 2/ 1972 Morikawa 260-666 B OTHER REFERENCES Hine, Physical Organic Chemistry," 2nd ed., McGraw- Hill Book Co., Inc., N.Y. (1962), pp. -61.

DANIEL E. WYMAN, Primary Examiner P. F. SHAVER, Assistant Examiner U.S. Cl. X.R.

252-429 A, 429 B, 431 P, 431 R 

